MRI resonator system with stent implant

Abstract

A stent is adapted to be implanted into the lumen of a vessel. The stent includes struts and a resonating circuit tuned to the resonating frequency of a magnetic resonance imaging system. The resonant circuit is constructed of at least one inductor and at least one capacitor. The inductor is wound about at least one of the struts.

1. A stent adapted to be implanted into the lumen of a vessel, the stent comprising a plurality of struts defining an interior and a resonating circuit, the resonating circuit comprising at least one inductor and at least one capacitor, the resonating circuit having a resonant frequency substantially equal to the frequency applied by a magnetic resonance imaging system, the at least one inductor in electrical communication with the at least one capacitor, the at least one inductor being a coil wrapped about only one strut of the plurality of struts, the strut having a longitudinal axis, the at least one capacitor being a substantially tubular device disposed about the strut such that the longitudinal axis of the strut extends substantially parallel to a longitudinal axis of the capacitor, wherein the resonating circuit encircles the interior of the stent at least once. 
   
   
     2. The stent of  claim 1  wherein the struts are metallic. 
   
   
     3. The stent of  claim 2  wherein the struts are niobium. 
   
   
     4. The stent of  claim 2  wherein the struts are nitinol. 
   
   
     5. The stent of  claim 2  wherein the struts are biodegradable metal. 
   
   
     6. The stent of  claim 1  wherein the struts are made from a polymer. 
   
   
     7. The stent of  claim 1  wherein at least one strut has a length, a thickness, and a width, along the length the strut defines a notched region, the notched region having a thickness less than the thickness of an adjacent region of the strut. 
   
   
     8. The stent of  claim 7  wherein along the width the notched region has a width less than the width of an adjacent region of the strut. 
   
   
     9. The stent of  claim 1  wherein at least one strut has a length, a thickness, and a width, along the width the strut defines a notched region, the notched region having a width less than the width of an adjacent region of the strut. 
   
   
     10. The stent of  claim 9  wherein along the length the notched region has a thickness less than the thickness of an adjacent region of the strut. 
   
   
     11. The stent of  claim 1  wherein the inductor is disposed about the at least one capacitor. 
   
   
     12. The stent of  claim 1  wherein the capacitor is disposed about the at least one inductor. 
   
   
     13. The stent of  claim 1  wherein the at least one capacitor is ring-shaped. 
   
   
     14. The stent of  claim 1  wherein the at least one capacitor is a stub. 
   
   
     15. A method of making and using MRI resonating system with a stent implant comprising the steps of:
 providing a resonating circuit, the circuit comprising at least one inductive element and at least one capacitive element, the circuit having a resonant frequency substantially equal to the frequency applied by a magnetic resonance imaging system; 
 wrapping the inductive element about only one strut of a stent, the stent having an interior, wherein the resonating circuit encircles the interior of the stent at least once; 
 disposing the capacitive element about the stent strut, wherein the capacitive element is a substantially tubular device; 
 placing the MRI resonating system within a body lumen; and 
 applying an MRI signal. 
 
   
   
     16. The method of  claim 15  further comprising the step of forming a notched region on the strut. 
   
   
     17. The method of  claim 16  wherein the inductive element is disposed about the notched region of the strut. 
   
   
     18. The method of  claim 15  wherein the capacitive element is disposed about the stent strut before the inductive element is wrapped about the strut. 
   
   
     19. The method of  claim 15  wherein the capacitive element is disposed about the inductive element. 
   
   
     20. A stent adapted to be implanted into the lumen of a vessel, the stent comprising struts defining an interior and a resonating circuit, the resonating circuit comprising at least one inductor and at least one capacitor, the resonating circuit having a resonant frequency substantially equal to the frequency applied by a magnetic resonance imaging system, the at least one inductor in electric communication with the at least one capacitor, the at least one inductor being a coil, at least one strut having a length, a thickness, and a width, along the width the strut defines a notched region, the notched region having a width less than the width of an adjacent region of the at least one strut, the coil being wound about the notched region of the strut, the capacitor being a tubular member disposed about the strut, wherein the resonating circuit encircles the interior of the stent at least once.